The human knee comprises an articulation of the femur, the tibia and the patella. The femur and the tibia are maintained in a condition of stable articulation by a number of ligaments of which the principal ones are the anterior and the posterior cruciate ligaments and the collateral ligaments. The rupture of the anterior cruciate ligament (ACL) is relatively commonly encountered as a result of sporting injury or the like. This rupture leads to knee instability and can be a debilitating injury. Though less common, the rupture of the posterior cruciate ligament (PCL) can be equally disabling.
When a ligament such as the ACL is damaged or torn, a replacement ligament or graft is often installed in the knee to reconstruct the natural ligament. During reconstruction of the ACL, for instance, a tunnel is typically drilled through an anterior portion of the tibia upwardly through a tibial plateau and another tunnel is drilled from the tibial tunnel into a distal end of the femur to approximate the original or natural position of the ACL. A bone-tendon-bone autograft is then harvested, often from the patellar tendon, following standard grafting procedures. A graft is then secured in the tunnels by fixation means, such as, for example, interference screws or sutures tied to screw posts. Optionally, autografts may include the hamstrings or central quadriceps tendon
Once the tibial attachment site for the ACL graft is determined, a drill guide is positioned onto the bone at the requisite positioning for drilling the tibial tunnel. A tibial drill guide mechanism guides a K-wire (wire drill) from a point below the knee joint to the former ACL tibial attachment site. A cannulated drill bit is overdrilled on the K-wire forming the tibial tunnel. The drill sleeve and guide mechanism are then removed leaving the K-wire or substituted guide pin in place. If desired, a cannulated reamer is used to broach the posterior cortex.
During the course of the above procedures, surgical instruments are repeatedly inserted into and removed from the tibial tunnel. For example, a back cutting burr is passed into and out of the hole several times to create a uniform tunnel edge, a guide pin may be substituted for the K-wire, and the geometry of the drilled hole is assessed to ensure isometry with the femoral tunnel. In addition, femoral aimers, reamers, tensiometers, and the like, may also be inserted and passed into the tibial tunnel. Care must be taken, however, not to damage or enlarge the drill hole or to create additional bone fragments, particularly, at the edge of the tunnel (which has been smoothed and chamfered) to prevent abrasion and potential damage to the graft. During the entire surgical procedure, fluid is placed into the joint via a pump or gravity to maintain distension of the capsule to improve visibility. Once the tibial tunnel is created, there is a natural and undesirable tendency for fluid to drain out of the joint, through the tunnel thus reducing joint distention and/or reducing visibility through the arthroscope and access to the anatomy. If the knee is allowed to drain to the point that it is substantially without fluids, the procedure may be delayed while proper distension is again established. Less than optimal visualization may compromise the surgical results. Currently marketed devices for sealing the tibial tunnel tend to fall out of the tibial tunnel, sometimes onto the non-sterile floor. Fluid pressure in the joint, manipulation of instruments, and gravity can cause failure of existing screw in or pressure fit devices. Some existing devices are solid and will not allow instruments to pass into the joints.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.